The title compound, [Eu(CH3CN)3(BF4)3)x, 1, was synthesized by the NOBF4 oxidation of metallic Eu in CH3CN. The interaction of the BF4- ions with the Eu(III) center was established by molecular weight, conductivity, and 11B and 19F NMR spectral measurements. 1 was found to exist as a dimer in CH3CN. In addition, it behaved as a 1:2 electrolyte, indicating the coordination of two of the BF4- ions per Eu(III) ion. However, the conductivity increased when chelating amines were added due to the partial displacement of the coordinated BF4- ions. The 11B and 19F NMR spectra of 1 in CH3CN indicated the presence of two different types of BF4- anions, one of which was isotropically shifted due to interaction with the paramagnetic Eu(III) center. The coordinated BF4- anions could be displaced quantitatively by the addition of 2 equiv of N03- ions per Eu(III) ion. A degenerate metathesis of the fluorine between the BF3 and the coordinated BF4- ions was observed when BF3 was added to a CH3CN solution of 1. 1 formed a charge-transfer complex with tetra-p-anisylethylene in CH3N02 but not in CH3CN. In addition, 1 initiated the oligomerization and the polymerization of styrene, a-methylstyrene, and 1, 3-cyclohexadiene in CH3N02. The molecular weights of the polymers obtained increased markedly on lowering the reaction temperature. At room temperature, indan derivatives were obtained from a-methyl- and a-phenylstyrene. The rate of polymerization of styrene was markedly attenuated when CH3CN was used instead of CH3N02. 1 also initiated the isomerization of quadricyclane and the ring-opening polymerization of 2(10)-pinene and cyclopropylbenzene in CH3N02.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry